The function try_enable_preferred_console() currently has the
non-obvious side effect of returning success for consoles that are
already pre-enabled. This obscures the logic flow during console
registration.
Move the check for pre-enabled consoles directly into
register_console(). This change makes the handling of pre-enabled
consoles explicit and easier to follow.
Furthermore, this separation lays the groundwork for future cleanups
where try_enable_preferred_console() can be restricted to cases where
an entry actually exists in the preferred_consoles[] array.
Possible behavior change:
try_enable_preferred_console() will newly be called also with
@user_specified parameter set to "false" when it failed with the "true"
variant. But it looks like the right way to do. It will allow to call
newcon->setup() when the console was preferred by some platform
specific code.
Signed-off-by: Petr Mladek <pmladek@suse.com>
---
kernel/printk/printk.c | 19 ++++++++-----------
1 file changed, 8 insertions(+), 11 deletions(-)
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index eb224eaace64..db91be780de9 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -3913,9 +3913,6 @@ static int console_call_setup(struct console *newcon, char *options)
* the newly registered console with any of the ones selected
* by either the command line or add_preferred_console() and
* setup/enable it.
- *
- * Care need to be taken with consoles that are statically
- * enabled such as netconsole
*/
static int __try_enable_preferred_console(struct console *newcon,
bool user_specified,
@@ -3963,14 +3960,6 @@ static int __try_enable_preferred_console(struct console *newcon,
return 0;
}
- /*
- * Some consoles, such as pstore and netconsole, can be enabled even
- * without matching. Accept the pre-enabled consoles only when match()
- * and setup() had a chance to be called.
- */
- if (newcon->flags & CON_ENABLED && pc->user_specified == user_specified)
- return 0;
-
return -ENOENT;
}
@@ -4178,6 +4167,14 @@ void register_console(struct console *newcon)
if (err == -ENOENT)
err = try_enable_preferred_console(newcon, false);
+ /*
+ * Some consoles, such as pstore and netconsole, can be enabled even
+ * without matching. Accept them at this stage when they had a chance
+ * to match() and call setup().
+ */
+ if (err == -ENOENT && (newcon->flags & CON_ENABLED))
+ err = 0;
+
if (err)
goto unlock_free;
--
2.52.0